Method of manufacturing briquettes



Dec. 1, 1953 T N 2,661,326

METHOD OF MANUFACTURING BRIQUETTES Filed April 5, 1948 4 Bituminous Coal Heat to reduce swelling Cool Grind to pass through 60 mesh Ground mineral" pitch to form from 5% to IO"/ by weight of the carbonaceous material Ground ligneous material to form I591, by weight of the carbonaceous material Fill receptacle made of solid carbonaceous material and composed of a plurality of small compartments Subject filled container to temperature of IOOOE in closed retort under lowered vapor pressure for about an hour INVENTOR Albert Leeds Stillman MA'V VW ATTORNEYS Patented Dec. 1, 1953 UNITED STATES FATE-N OFFICE} METHOD OF 'MAN'UFACTUBING BRIQUETEEE S1.

ApplicationAprilzii, 1948 ,;ScIf-ia1 Nul9r160.

ZCIaims. (01. 202 -25) This in vention 1 relates to the manufacture of briquettes, and more particularly to improvements: in the production of* smokeless; coal briquettes.

The primary purpose of the invention is to provide-a process by which, asmolseless rapidly and :evenly' burning briquette ;of convenient :size can-be made in an inexpensive manner. 1

The briquette of this invention is composed of finely' powdered coal, preferably a bituminous orsemi-bituminous coalwhich ordinarily-would swell when-heated; such as thosecoalsknown as Pocahontas and-Lower -Kittaning. The coal is=first heated in -a--drying--apparatus at a temperature ofnot less than-350-degrees and-not more than 400 -degrees-F-=-for aperiod of about ten minutes, andythienpistcoolcd at atmospheric temperature. As a result ,of ,this treatment, the.

swelling, quality of the coal. .is practically eliminated. The coal is then ,gIjound finely so..that the whole passes through a sieve of from 60'to 200 meshes per linear inch.

The thus treated coal may be utilized as the carbonaceous matter of the briquette, or the latter may be composed of a mixture of such coal and pitch, or a mixture of such coal, pitch and ligneous material. It is preferred that the carbonaceous matter of the briquette include from '5 to by weight, of a mineral pitch, such as oil asphalt (also called refiners waste) having a melting point of approximately 300 degrees F. The pitch or asphalt is first ground to pass wholly through a sieve of from 60 to 200 meshes per linear inch, and then mixed in any suitable fashion with the heat treated, ground coal. It .is also preferred that the carbonaceous matter of the briquette include approximately by weight, of ligneous material, such as sawdust or ground sugar cane waste. This material may be added with the pitch to form the mixture or may be intermixed with the mixture of coal and pitch.

Whether the finely ground carbonaceous material be composed Wholly of coal, or a mixture of coal and pitch, or a mixture of coal, pitch and ligneous material, such material is then placed in a receptacle divided by partitions into a plurality of compartments or cells. The receptacle is preferably a rectangularly-shaped open receptacle about two inches high and divided into compartments or cells of about four square inches in area; the top edges of the partitions being flush with the top edges of the receptacle. The material of the receptacle as well as the partitions thereof, is made of combustible material, such as wood or paper. In filling the compartmentsor cellsofthe receptacle, suffie ofhthereceptacle, and its partitions, Inother words,,,the.comp,attment's or cellsare completely.

filled with thecarbonaceous material. Thefilled. receptacle ,isgthenplaced in a closedretortand heated.in the latter under lowered .vapor tension obtained..-.by, pumping, out theatmosphere in, the; retortby means,of. .a,pump. Thcretort is exeternally, heated,v to. a. temperature, of approxi-- mately,1000.;de IeesE. and the filled receptacle:

is, .,subj.ectcd ,to. -.suc h, temperature in the retort sufficiently drivenzfrom.thecarbonaceous mate:

ria ias. to. render1 .itpractically-smokeless, At. theend. of... that. .,per,iod,. ,the. carbonaceous material wi11.. all.e carbonized. into. rectangular shapes .of thercompa itmentsl and the material. of .there ceptacle will;'h'ave carbonized into. a, fragile .carr' bon' so that'the whole mass may be readily broken into rectangularly-shaped briquettes of convenient size for burning and handling.

The principal steps of the above described method in the form of a flow sheet are shown on the accompanying drawing.

It will be noted from the foregoing that the briquette of this invention is composed of from about to approximately of carbonized coal and that portion of the fragile carbon resulting from the receptacle and adhering to the carbonized carbonaceous material in the briquette when the carbonized mass is broken up into briquettes. As has previously been mentioned, the coal may be either of the bituminous or semi-bituminous type, hence, where in the appended claims reference is made to bituminous coal, it is to be understood that such term also includes semi-bituminous coals. The purpose of preheating the coal at a temperature of from 350 degrees to 400 degrees F. is to prevent any danger of the coal breaking the partitions of the receptacle during the carbonizing step. As a further result of such preheating treatment and the carbonizing of the carbonaceous material in the retort, a large part of the non-flammable gases in such material is driven off, thereby enabling the finished briquettes to be lighted readily, to burn evenly and completely, and to be easily tended. These qualities of the briquette are enhanced by the presence of the ligneous material which lightens the briquette and increases its friability. The process of making the briquettes of this invention is simple and inexpensive and obviates the necessity of using a temperature of from 350degrees F. to 400 degrees F. for ten minutes, cooling the thus treated coal to atmospheric temperature, grinding the treated coal until it passes wholly through a sieve of 60 mesh, mixing with the coal ground mineral pitch and ligneous material to form a finely powdered carbonaceous material in which the pitch forms approximately 5% to by weight, of such carbonaceous material, the ligneous ma terial forms approximately, by weight, of such carbonaceous material, and the ground, treated bituminous coal forms approximately from 75% to 80% by weight, of such carbonaceous material, filling a receptacle made of solid cellulose material and composed of a plurality of small compartments with the powdered carbonaceous material, and then subjecting the filled container to a temperature of approximately 1000 degrees F. in a closed retort under lowered vapor tension for about one hour to convert the carbonaceous material into carbonized low temperature char and to convert the cellulose material of the receptacle into layers of fragile carbon on the surfaces of the briquettes.

2. The method of manufacturing briquettes, which comprises heat treating a bituminous coal to eliminate any substantial tendency to swell. grinding the thus treated coal until it passes wholly through a sieve of mesh, mixing with the coal approximately 5% to 10% by weight, of ground mineral pitch to form a finely powdered carbonaceous material, the ground bituminous coal being mixed with the ground pitch in suflicient quantity to form approximately from to by weight of the carbonaceous material. mixing with the coal' and pitch, approximately 15% by weight, of ligneous material, filling a receptacle made of solid cellulose material and composed of a plurality of small compartments with the powdered carbonaceous material, and then subjecting the filled container to a temperature of approximately 1000 degrees F. in a closed retort under lowered vapor tension until the carbonaceous material has been converted into carbonized low temperature char and the cellulose material of the receptacle has been transformed into layers of fragile carbon on the surfaces of the briquettes.

ALBERT LEEDS STILLMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 415,734 Randall Nov. 26, 1889 1,481,942 Vogel Jan. 29, 1924 1,561,322 Goskar Nov. 10, 1925 1,593,208 Culmer July 20, 1926 1,618,248 Walton Feb. 22, 1927 1,772,053 McIntire Aug. 5, 1930 2,105,832 Becker Jan. 18, 1938 2,158,666 Otto May 16, 1939 2,314,641 Wolf Mar. 23, 1943 2,341,861 Fuchs Feb. 15, 1944 FOREIGN PATENTS Number Country Date 279,020 Great Britain Dec. 22, 1927 499,432 Great Britain Jan. 24, 1939 

1. THE METHOD OF MANUFACTURING BRIQUETTES, WHICH COMPRISES SUBJECTING A BITUMINOUS COAL WHICH ORDINARILY WOULD SWELL WHEN HEATED TO A TEMPERATURE OF FROM 350 DEGREES F. TO 400 DEGREES F. FOR TEN MINUTES, COOLING THE THUS TREATED COAL TO ATMOSPHERIC TEMPERATURE, GRINDING THE TREATED COAL UNTIL IT PASSES WHOLLY THROUGH A SIEVE OF 90 MESH, MIXING WITH THE COAL GROUND MINERAL PITCH AND LIGNEOUS MATERIAL TO FORM A FINELY POWDERED CARBONACEOUS MATERIAL IN WHICH THE PITCH FORMS APPROXIMATELY 5% TO 10% BY WEIGHT, OF SUCH CARBONACEOUS MATERIAL, THE LIGNEOUS MATERIAL FORMS APPROXIMATELY 15% BY WEIGHT, OF SUCH CARBONACEOUS MATERIAL, AND THE GROUND, TREATED BITUMINOUS COAL FORMS APPROXIMATELY FROM 75% TO 80% BY WEIGHT, OF SUCH CARBONACEOUS MATERIAL, FILLING A RECEPTACLE MADE OF SOLID CELLULOSE MATERIAL AND COMPOSED OF A PLURALITY OF SMALL COMPARTMENTS WITH THE POWDERED CARBONACEOUS MATERIAL, AND THEN SUBJECTING THE FILLED CONTAINER TO A TEMPERATURE OF APPROXIMATELY 1000 DEGREES F. IN A CLOSED RETORT UNDER LOWERED VAPOR TENSION FOR ABOUT ONE HOUR TO CONVERT THE CARBONACEOUS MATERIAL INTO CARBONIZED LOW TEMPERATURE CHAR AND TO CONVERT THE CELLULOSE MATERIAL OF THE RECEPTABLE INTO LAYERS OF FRAGILE CARBON ON THE SURFACES OF THE BRIQUETTES. 